Analysis of Radio Interference from Short Multiconductor Lines Part 1: Theoretical Analysis

Radio Interference (RI) measurements made on short single-conductor or multiconductor test lines are generally used to predict the RI performance of the corresponding long lines. A rigorous analysis is presented in this paper of RI propagation on short lines including the influence of different impedance terminations at the ends of the line. The method consists essentially of the modal propagation analysis which takes into account the effect of line terminations. It is shown that the short-line analysis developed in the paper can also be extended to the case of long lines, which automatically takes into account the correct method of adding the modal components. Analytical results obtained by applying this analysis to practical line configurations, and some comparisons with experimental results, are presented in a companion paper.